一种基于Logistic映射的水声混沌信号测距方法

在浅海水声定位系统中,针对传统声呐信号持续时间长、效率低、正交性差的问题,提出了一种抗噪声、快速、窄带的水声混沌信号。通过推导Logistic混沌序列的混沌性和相关特性;并据此将具有混沌特性的相位信息对混沌序列进行调制。理论表明调制后的水声混沌信号具有正的Lyapunov指数、理想的相关性和窄带性。水域数据分析显示,水声混沌信号依旧表现出混沌性和窄带性;并且与同水域实验的m序列相比,定位精度提高了5 cm左右,信号时长缩短了73 ms,为海洋中动态目标的快速定位提供了参考。

An acoustic chaotic signal ranging methodbased on the Logistic mapping

In the shallow water acoustic localization systems,a kind of underwater acoustic cha- otic signal that is anti-noise,fast and narrowband is proposed for tranditional sonar signal being a long time,low efficiency and poor orthogonality.The chaos and correlation properties of Logistic chaotic sequences are dericed, and the chaotic sequence is modulated by the phase information wi- th chaotic characteristics.The theory shows that chaotic modulated signal of underwater acoustic chaotic signal has a positive Lyapunov exponent, ideal correlation and narrowband. Analysis of water experimental data show that underwater acoustic chaotic signal still puts up chaotic charact- eristics and narrowband,and compares with the m-sequence that the positioning accuracy improv- es the 4cm and the time of signal is shortened 73ms at the same waters .It provides a reference for the rapid localization of the dynamic target in the ocean.